A Transient Performance Enhancement Scheme for Dual-Stage Actuated HDD Servo System

For a dual-stage actuated (DSA) HDD servo control system, a large servo bandwidth is desirable to attain ultra-high accuracy in read/write head positioning, but the resonant modes hamper the achievement of such an essential high bandwidth. Aiming at the problem, we adopt a novel control scheme to achieve a transient performance enhancement. It is designed based on a newly developed feedback control methodology called integral resonant control (IRC). The primary coarse actuator voice coil motor (VCM) for facilitating large motion is regulated by reduced order composite nonlinear feedback (CNF) control approach, and the secondary piezoelectric micro-actuator (MA) for high-precision positioning is controlled through an IRC compensator together with a notch filter. Finally, we demonstrate the efficacy of the proposed control scheme through simulation validation.